In the known internal combustion engine, the plenum is attached to an end wall of the motor vehicle engine compartment. Relatively long intake runners lead rectilinearly from the plenum to the cylinder head. A throttle body with a throttle valve to control the quantity of air is provided at the inlet of the plenum. The air inducted by the internal combustion engine flows from an air intake tube through an air filter and the throttle body into the plenum, and from there through the individual intake runners into associated combustion chambers of the internal combustion engine.
The configuration of the intake system according to the above-mentioned U.S. Pat. No. 4,628,873 provides relatively long intake headers running rectilinearly, which leads to advantageous gas velocity conditions. This results in an increase in torque at low engine speeds, and reduces undesirable exhaust and noise emissions.
For reasons concerning the environmental compatibility of motor vehicles, it is advantageous if they are operated at relatively low engine speeds. However, drivers take advantage of the ability to drive at low to medium engine speeds only if sufficient torque is also available at the same time.